Paper coating apparatus



June 12, 1956 Flled Aug 17, 1953 m aa z Em am w June 12, 1956 o. E.HAGEN PAPER coATING APPARATUS 4 Sheets-Sheet 2 Filed Aug. 17. 1953 June12, 1956 o. E. HAGEN PAPER coATING APPARATus 4 Sheets-Sheet 3 Filed Aug.17, 1953 June 12, 1956 o. E. HAGEN PAPER COATING APPARATUS 4Sheets-Sheet 4 Filed Aug. 17, 1953 .z 26+ 24. f. x 6 76 w Ww 1 6 7 w m12/ -fi Hl W W l 2 f/ m 6 M AIR PAPER coA'rrNo APPARA'rUs Oscar E.Hagen, deceased, late of Neenah, Wis., by Frances M. Hagen, executrix,Neenah, Wis., assignor, by mesne assignments, to Kimberly-ClarkCorporation, a corporation of Delaware Application August 17, 1953,Serial No. 374,539

Claims. (Cl. IIR- 249) The present invention is directed to an improvedpaper coating apparatus for applying mineral pigments and the like topaper webs in the manufacture of high quality paper suitable for bookpaper and the like.

In one common system for applying mineral pigment coatings to a web ofpaper, the paper web is fed continuously into the nip between a pair ofcoating rollers, the nip being carefully adjusted to provide the properapplication pressure uniformly distributed across the web. Each coatingroll, in turn, receives its coating from a series of auxiliary rollsincluding a roll which is continuously .supplied with a Suspension ofthe pigment, this roll cooperating with a highly polished metering rollin surface contact with the first mentioned roll. The metering roll, inturn, transfers the coating from the first roll or backup roll, to atransfer roll disposed between the metering roll and the coating roll.The coating material thus is carried .successively over the surfaces ofthree rolls before it is applied to the surface of the main coatingroll.

In the production of high quality coated paper it is essential that thepressure at the area on the main coating roll at which the coatingcomposition is applied be carefully Controlled in order to provide auniform, smooth coating of Constant density along the moving paper web.It is equally important to achieve the correct Operating pressuresbetween the rolls making up the auxiliary train, as otherwise thecoating composition will not be applied uniformly or in properquantities to the surface of the main coating roll. It is also desirableto observe the proper surface characteristics between the rolls.Reference is made to Hoel U. S. Patent No. 2,606,520 for a descriptionof these relationships.

The adjustment of the pressure at the coating hip as well as theinter-roll pressure between the rolls in the auxiliary train must bewithin very close tolerances for best results. In commercialinstallations, however, the coating roll, as well as the auxiliaryrolls, must be quite massive in order to achieve the coating speedrequired in such machines. The substantial width required for the rolls,and the -substantial pressures involved for certain applications in thecoating application also contri'oute to the necessity of providingmassive rolls in such assemblies. For machines of about one hundredforty inches in width, the train of auxiliary rolls and its supportingframes weighs as much as fifteen tons, and the main coating rolltogether with its supports may weigh about ten tons. Hence, the -fineadjustment of inter-roll pressures becomes a very substantial problem.

It becomes particularly important in apparatus for coating both sides ofthe paper web, where pressures as light as five pounds per lineal inchmay be employed. In prior systems, the problems associated with securingthe correct Operating pressures were so diflicult, that simultaneouscoating of both sides of a paper web was not commonly practiced, andinstead, the web was coated on one side, dried, and then coated on theopposte side.

nited States Patent O 2,749,87s Patented June 12, 1956 ICC 2 Processesof this type involve the use of rather elaborate roll systems anddriers.

Any mechanical system for mounting rolls to make the pressures readilyadjustable must also take into consideration the problem of access tothe rolls during periods when the machine is to'be shut down forcleaning of the rolls or replacement of the rolls. Hence, the means tobe provided for adjusting the various contacting pressures between therolls should at the same time permit free access to the rolls when themachine is shut down.

One of the primary objects of the present invention is to provide apaper coating assembly with a balan'ced arrangement of rolls in whichthe rolls are so arranged that the force applied to the rolls in theauxiliary train and the pressure at the coating nip of the main rollscan be readily adjusted within very closely defined limits.

A further object of the invention is to provide a coating apparatus witha balanced roll arrangement whereby only a relatively small, finelyadjustable, pressure is required to shift the rolls into and out ofoperative engagement.

Another object of the invention is to provide an improved mountingassembly for metering and backup rolls in a paper coating arrangementwhich permits a rapid and closely controllable adjustment of thepressures between the rolls during the coating operation.

Another object of the invention is to provide a paper coating apparatuswhich permits greater freedom in control of the travel of the webthrough the paper coater and its contact with the coating applicatorsurface.

In general, the present invention provides an improved coating apparatusin which the main coating roll is supported on a pivotally mountedbalanced frame, and the rolls making up the auxiliary train aresupported on a supplemental frame which is pivotally mounted by the mainframe. With this arrangement, the auxiliary train is pivotally movableabout its own pivotal axis and at the same time is bodily movable uponpivotal movernent of the main frame about its axis. Pressure Sensitivemeans are also provided between the main frame and the supplemen'talframe in order to adjust the relative movernent between the two frameassemblies. Means are also provided for mounting some of the roll-s inthe auxiliary train in a manner such that movement of the supplementalframe into a position in which the auxiliary train is disengaged fromthe main coating roll will cause these rolls to move apart a sufiicientdistance to permit the cleaning of the surfaces of the rolls orreplacement of the rolls.

One of the primary features of the roll arrangement of the presentinvention resides in a substantial balance in distribution of mass abouta common aXis, the pivotal aXis of the main frame, when the rolls are inoperative engagement during the coating operation. This is accomplishedby distributing the mass along the main frame and the supplementalframe, so that the center' of gravity of the two assemblies is verynearly at the pivotal aXis of the main frame during the coatingoperation. The balance is not exact, however, as it is desirable to havea slight turning moment still present about this pivotal axis, thismoment being in a direction which would tend to open up the rolls, i. e.disengage them from abutting contact. This arrangement provides a safetyfeature whereby a failure in the actuating system will result in therolls separating by virtue of the mass of the rolls and the frameassemblies.

A more specific description of the invention will be made in conjunctionwith the attached sheets of drawings which illustrate the principles ofthe present invention applied to a machine for coating both sides of aweb of paper, although it Will be readily apparent that the principleswill be equally applicable to machines coating only one surface of amoving web of paper, and having more or less rolls than the number ofrolls indicated in the drawings.

1Eigure l is a view in elevation of the coating assembly iliustratingthe manner in whichthc various rolls are m'ounted;

Figure 2 is a view taken substantially along the line 2-2 of Figure l,the view being partially in cross section;

Figure 3 is a view taken substantially along the line 3-3 o Figure l andillustrating the means for supporting the metering roll;

Figure 4 is a fragmentary view in elevation and partially in crosssection of one of the pressure rcsponsive means which interconnect themain frame and the supplemental frame;

Fignre 5 is a view taken substantially along the line 5- 5 of Figure 4;and

Figure 6 is a cross-sectional view taken along the line 6-6 of Figure 5.

ln Figure l reference numeral 10 indicates generally a supporting framefor the coating assembly which supports the weight of most of theelements in that assembly. Keyed to the frame 19 is a pair of shaftsupports 11 (Figures l and 2) each of which receives a pivot pin 12which is journalled in a pair of bearings 13. The spaced pivot pins 12provide a pivotal axis for a main frame 14, composed of twosubstantially identical frame members, one on each side of the machine.One of these frame members is best illustrated in Figure 1. Each of theframe members making up the frame 14 at its upper end has a bearingsupport member 16 which journals the main coating roll 17 for rotationtherein. The roll 17 will usually be a rubber-covered roll of relativelylarge dimensions.

The auxiliary train of rolls generally indicated at 19 in the drawingsis supported on a supplemental frame or subframe 21 composed of twosubstantially identical frame members arranged to provide relativepivotal movement between the auxiliary train 19 and the main coatingroll 17. The supplemental frame 21 is received between the spaced lowerends -of the frame members consttuting the main frame 14. A pair ofpivot pins 22 carried by the main frame 14 provide a pivotal axis forthe movement of the supplemental frame 21 with respect to the main frame14, the pivotal aXis for the supplemental frame 21 being insubstantially the same horizontal plane as the pivotal axis of the mainframe 14.

One of the important features of the present inventicn resides in theproper distribution of the mass of the coating assembly. In thedescribed arrangement, a major part of the mass of the upper coatingpress unit (including the rolls 26, 28, 36, and 17) is carried at thepivot pins 12. With this arrangement, only a very small portion of themass acts as a dead weight on the roll adjusting means subsequently tobe described, so that less total force is necessary to move the rollsthrough a given increment than has heretofore been employed.

Secured to the top of the supplemental frame 21 is a framework 24 whichprovides support for the rolls making up the auxiliary train 19. Thetrain 19 includes a rubber-covered backup roll 26 journaled for rotationin spaced bearing supports 27 on the frame 24. The nip between the rolls26 and 28 is supplied with the pigmented coating through a pipe 30located above the rolls 26 and 28. A pair of end seals are provided, oneon each side of the machine to receive the excess coating from betweenthe surfaces of these rolls. A pipe is provided to recrculate thecoating composition not picked up by the rolls backinto the coatingvsupply system feeding the pipe 30.

The metering roll 28 is usually composed of chromium plated steel orother composition and is mounted for rotation in brackets 29, the latterhaving collars 31 (Figure 31) which engage pins 32 for pivotal' movementabout the axes of the pins. As best seen in Figure 1, the axes of thepins 32 are displaced laterally from the axis of rotation of the roll 23so that as the supplemental frame 21 is pivoted about the pins 22 in acounterclockwise direction, the metering roll 28 will fall by its ownweight into spaced relation with respect to the backup roll 26. Stops3-4 are positioned to engage the brackets 29 and thereby limit thedistance through which the roll 23 can be displaced from the roll 26. Inpractice, the amount of relative movement permitted between the surfaceof the roll and the roll 28 will be on the order of 4 to 6 inches sothat When the rolls are disengaged the surface of the roll 26 and theroll 28 will be readily accessible for Cleaning.

in a similar manner, a transfer roll 36, consisting of a resilicntcovered roll of substantial diameter, has a shaft 37 journalled forrotation in opposed bearings 38 (Figure 2). The transfer roll 36 isdisposed over a pan 39 which serves as a reservoir for coating materialdropped from the surface of the roll 36.

The bearings 38 are provided at their lower ends with collars LS-.twhich engage pivot pins 42, as best seen in Figure 2. The pins 152 arealso laterally displaced from the aXis of rotation of the shaft 37 inthe same manner that the rotational axis of the metering roll 28 isdisplaced from the axes of the pins 32. Hence, when the supplementalframe 21 is pivoted about the pins 22 in a counterclockwise direction,both the metering roll 28 and the backup roll 26 will pivot due to theirown weight in a clock Jise direetion about their respective pivots. Whenthe supplemental frame 21 has been pivoted a sufficient amount in thecounterclockwise direction, the metering roll 28 and the transfer roll36 will be spaced from each other and from the surface of the maincoating roll 17. A pair of stops 43 are provided in the frame 21 tolimit the are through which the transfer roll 36 may be pivoted.

The distribution of the mass of the roll and frame assemblies should becarefully adjusted to take advantage of the balanced arrangement. Withthe arrangement shown, the center of gravity of the supplemental frame21 and the auxiliary train 19 is somewhat to the left of the axis of thepins 22 when the rolls in the auxiliary train are in the open ornon-abutting position. As the assembly is pivoted clockwise about thepins 22, however, the center of gravity shifts slightly, but stillremains slightly to the left of the axis of the pins 22 when thc rollsof the auxiliary train are in operative engagement. This arrangementsubstantially reduces the force required to secure an incremental changein the pressure between the rolls, while at the same time permitting therolls to be biased toward their disengaged positions by virtue of themass of the rolls in the event that failure in the pressure adjustingmechanism should occur.

The combined masses of the main frame 14 (including the roll 17) and thesupplemental frame 21 (together with the auXiliary train 19) has itscenter of gravity slightly to the left of the pins 12 when the rolls aredisengaged. As the rolls are brought into operative engagement bypivoting of the entire assembly about the pins 12, the center of gravityshifts slightly, but still remains slightly to the left of the axis ofthe pins 12 when all the rolls are in operative engagement. ln thiscondition, most of the mass of the assembly is carried at the pivot pins12, leaving only a slight dead weight to be absorbed at the pressureregulating mechanism. As a result, only a small amount of force isrequired to change the pressure relationships, and the rolls are stillbiased toward their open position so that they may be automaticallydisengaged in the event of failure in the pressure regulating mechanism.

A wide range, closely adjustable control over the internal pressuresbetween the rolls making up the auxiliary train 19 is aforded byproviding a combined hydraulically operated and a fluid pressureoperated means such as an air pressure system Working in series, thehydraulic means being used to achieve a coarse adjustment of the rollposition, and the air pressure being used to achieve the final fineadjustment of nip pressure. While a hydraulically operated system is thepreferred adjustment means, this positioning mechanism may comprisemechanical arrangements such as toggles, screws, and the like which willprovide a positive, controllable positioning means.

As will be seen from Figures 1 and 4, the lower end of the frame membersmaking up the supplemental frame 21 are secured to shafts 44 which arereciprocable by operation of the fluid pressure-operated displacementmeans, best illustrated in Figures l, 5, and 6 of the drawings. Coarseadjustment of the relative positions of the supplemental frame withrespect to the main frame is achieved by means of a cylinder 47 in whicha piston 48 at the end of the shaft 44 is free to reciprocate. Near oneend of the cylinder, an annular internal stop member 49 (Figure 4) isprovided to provide a stop for the movement of the piston 48 within thecylinder 47. Oil or other liquid is introduced into or discharged fromthe righthand or piston end of the cylinder 47 through a line 51, andanother line 52 is provided for conducting oil or other fluid to or fromthe other end of the cylinder 47.

In the initial adjustment of the rolls in the auxiliary train 19, oilpressure is applied to the piston 48 until the piston reaches theinternal stop 49. The oil pressure introduced should be more than enoughto cause the piston to be bottomed against the stop 49. In thisposition, the roll 36 is in contact with the surface of the roll 17 byvirtne of the bias provided by the off center pivot of that roll.Similarly, the metering roll 28 is also in contact with the surface ofthe roll 36 because of its off center pivotv With the piston 48 bottomedagainst the stop 49, the roll 26 should still be approximately one inchfrom engagement with the surface of the metering roll 28.

The fine adjustment of the roll pressures in the metering train isaccomplished by means of air pressure systems, one of which isillustrated in Figures 5 and 6 of the drawings. This system includes apair of diaphragm housing plates 54 and 55 secured together at theirperipheries by means of circumferentially spaced bolts 56. Clampedbetween the plates 54 and 55 is a flexible rubber diaphragm 57 whoserelative position is determined by the amount of air pressure introducedinto the diaphragm housing through spaced ports 58 on the outer side ofthe diaphragm 57. The movement of the diaphragm 57 in response toincreased air pressure is transmitted to a diaphragm plate 59 rigidlysecured to a rod 61. The end of the cylinder 47 is also fixedly securedto the rod 61 so that movement of the diaphragm plate 59 will also serveto move the cylinder 47 in response to air pressure introduced into thediaphragm assembly. The piston 48 remains bottomed against the internalstop 49 as long as sufficient oil pressure is maintained within thecylinder 47.

The rod 61 also receives a pair of studs 62 in threaded engagernent. Thestuds 62 are carried in collar 64 provided on an arm 66. The studs 62are free to slide a limited amount within slots provided in collars 68extending from an arm 69. The upper ends of the arms 66 and 69 receive apin 71 which permits relative movement between the arms. In order toavoid the possibility of excessive flexing of the diaphragm 57 in eitherdirection, the collars 68 are provided with threaded studs 72 whose endsextend into the slots in which the studs 62 slide and form variable stopmeans for limiting the displacement of the rods 61.

The sequence for adjusting the pressures in the auxiliary train 19therefore consists in introducing oil under pressure .into the cylinder47 until the piston 48 is bottomed against the internal stop 49. Aspreviously explained, in this position the roll 26 will be separated bya small amount from the surface of the roll 28. A final adjustment ofthe roll pressure and position is accomplished by introducing air orother fluid pressure against (i the diaphragm 57 and thereby move thecylinder and piston assembly further to the left as viewed in Figure 1.The movement of the piston and of the shaft 44 thereupon causes thesupplemental frame 21 to be pivoted about the pins 22 in a clockwisedirection. Air pressure is then continuously intro-duced until such timeas the roll 26 contacts the surface of the metering roll 28 with thed'esired pressure. As previously explained, the rolls in the auxiliarytrain 19 when in operative engagement are still biased slightly towardtheir disengaged condition by their own mass supplying a slight turningmoment in a counterclockwise direction about the pins 22.

The assembly for coating the opposite side of the paper is substantiallythe same as that previously described for coating the top surface of apaper web W as it advances through the machine. As evident from Figurel, the web W in entering the coating machine passes under a spreadingroller 76 or bar and over a roller 77 before it enters the coating nipexisting between the main coating roll 17 and a coating roll 78 on theopposite side of the web W. The auxiliary train for applying the coatingcomposition to the roll 78 is indicated at 79 and includes a transferroll 81, a metering roll 82, and a backup roll 83. The coatingSuspension is supplied to the nip between the rolls 82 and 83 from apipe 90. The transfer roll 81 is mounted for rotation in a bracltet 84,and is biased toward the roll 78 since the bracket 84 is pivotallysecured to the frame assembly by pivot pins 86 which are laterallydisplaced from the rotational axis of the roll 81. Similarly, themetering roll 82 is biased toward the transfer roll 81 by providing abracket 87 pivoted by means of an off center pivot 88 to the main frameassembly.

The supports for the auxiliary train 79 consist of a pair of framemembers 89 which are pivoted at a pair of spaced pivot pins 91. Thelower ends of the frames 89 are secured to shafts 92 which arereciprocated by the operation of the pistons in hydraulic cylinders 93of the same type as previously described. The fine adjustment of theroll pressures in the train 79 is accomplished by means of controllingthe fluid pressure in a set of diaphragm assemblies 94 substantiallyidentical with those previously described. As in the auxiliary train 19,the mass of this coating system is also distributed so that when therolls are in operative engagement for coating, they are still biasedslightly toward their open condition, in this instance, in the directionwhich would pivot the frame members 89 in a clockwise direction aboutthe pins 91.

The movement of the main frame assembly 14 which adjusts the pressure ofthe coating nip between the roll 17 and the roll 78 is controlled byanother combined oil pressure and air pressure system. Each of the framemembers making up the main frame 14 has an extension 96 secured to ashaft 97 which is reciprocable in response to oil pressure introducedinto a cylinder 93 and acting against a piston carried by the shaft 97,the arrangement being substantially identical with that shown in Figure4 of the drawings. When the piston becomes bottomed against the internalstop provided in the cylinder 98, air is introduced into a diaphragmassembly 99 to move the piston and cylinder bodily until the proper nippressures are achieved.

The complete adjustment of the machine thus comprises the followingsteps. First, the inter-roll pressures in the auxiliary train 19 areadjusted by introducing oil pressure into the cylinders 47 until theroll 26 is spaced only a small amount from the roll 28. Next, airpressure is introduced into the diaphragm assemblies through the inlets58 until the roll 26 contacts the roll 28 with the proper pressure.Similarly, the pressure betweeen the rolls in the train 79 is adjustedby control of the oil prssure in the cylinders 93 and the air pressurein the diaphragm assemblies 94.

The coating roll is then positioned by introducing suficient oilpressure into the cylinders 98 to cause the main frame 14 to pivot aboutthe pivot pins 12 in a clock- Wise direction. Since the supplementalframe 21 is carried by the main frame at the pivot pins 22, the pivotalmovcment of the main frame about its axis moves the suppiemental framebodily With the movement of the main frame 1d so that the rolls in theauxiliary train 19 are ltept in the same relative position and under thesame pressures during the movement of the main coating roll i7. rfhefinal adjustment of roll pressures is accomplished by introdueing airpressure into the diaphragm assembly 99. in the finally adj-ustedposition, very little of the mass acts against the shaft 97, so thatonly a very slight force is required to change the pressure relationshipof the rolls.

Upon admission of air pressure and oil pressure to the diaphragmassernblies 99 and the cylinder 9d, respectiyely, the main coating rollsare engaged as the main frame iii pivots about the pins 12. When the oilpressure is reduced in the cylinders 47 and the air pressure is removedfrom the corresponding diaphragrn assemblies, the supplemental frame 21will be pivoted in a counterclochwise direction and the off centerpivots provided on the rolls 26 and 3d Will cause those rolls to move bytheir own Weight into spaced relation With each other and into spacedrelation with the roll 26.

One convenient means for achieving the proper small amount of unbalanceinto the system is by correlating the air pressure required tocounteract the dead weight imposed on the air pressure operateddiaphragm with the maximum rated pressure of the diaphragm. The lattervalue is set by the diaphragm manufacture, and represents the maximumair pressure which the diaphragm can be expected to withstand duringnormal operation. For the purposes of this invention, the amount ofpressure on the diaphragm required to overcome the dead weight imposedon the pressure regulating mechanism should be from about 5 to 25 percent of the rated diaphragm pressure, and preferably about per cent.When the mass of the coating assembly is distributed so that this cond'on obtains, there is still a relatively small amount of biasmg on therolls tending to disengage the rolls automatically upon failure of thepressure regulating means, but there is present a considerable Workingrange of air pressure available to actuate the diaphragm to controlaccurately the nip pressures in the coating assembly.

The assembly described provides a very convenient means for accuratelyadjusting roll pressures in a coating assembly and also for adjustingthe pressure at the coatmg nip. With the system described, it ispossible to make very fine adiustments of the various roll pressures tocompcnsate for irregularitics in paper thickness, differences in paperbasis weights, viscosity of the coating solutions, and other variableswhich occur in a paper coating process and which must be compensated toachieve perfect coatingr of the paper.

lt will be evident that various modifications can be made to thedescribed apparatus without departing from the scope of the presentinvention.

What is clairned is:

l. in a paper coating machine, a roll assembly comprising a main coatingroll arranged to apply a coating composition to one side of a Web ofpaper, a train of auxiliary rolls arranged to transfer said coatingcomposition successively along said rolls and onto said main Coatingroll, a pi'v'otall'y mounted frame supporting said main roll, a,suoframe supporting said train, means on said frame providing a pivotalaxis for said subframe and means on said subframe for pivotally mountingat least one of the rolls in said train along an axis laterally offsetfrom the axis of rotation of said one roll Whereby pivotal movement ofsaid subfranie With respect to said frame will cause said one roll tomove away from an adjoining roll in said train, the combination of saidframe, said 8 subframe, and said rolls having a center of gravity whensaid rolls are in operative engagement only slightly displaced from thepivotal axis of said frame in a direction which urges said rolls out ofoperative engagement.

2. ln a paper coating machine, a pair of axially hori- :omal parallelrolls through the nip of which the i er passes and to which papercoating-mixture is applied by one of said rolls, the nip and axcs ofsaid rolls located in a planc which is nearer Vertical than horizontal,a main frame carrying the applicato-r roll and adapted to on ahorizontal axis spaced from said said last-named axis and the nip beinglocated in second plane which is generally pcrpendicular to thefirstmentioned plane, a subframe pivoted on said main frame to rock on ahorizontal axis, coating-mixture supply mc'tns including an aY-.iallyhorizontal roll carried by said nted to contact the applicator roll toz, ure thereto, the axes of the supply and applicator rolls beinglocated in a third plane intersecting the first-named plane at an anglewhich is closer to than to 0, the center of gravity of the main frameand parts carried thereby being located in a vertical plane notmatcrially spaced from the axis of said main frame, means for rocltingsaid main frame to apply pressure to the pa er-coating nip, and meanscarried by the main frame for rocking said subframe to bring said supplyroll into contact with the applicator roll.

3. ln a paper coating machine a pair of axially horizontal parallelrolls through the nip of which the paper passes and to which papercoating-mixture is applied by one of said rolls, the nip and axes ofsaid rolls being located in a plane which is nearer Vertical thanhorizontal, the applicator roll being the upper roll, a main framecarrying the applicator roll and adapted to rocl; on a horizontal axisbelow, and spaced from, said hip, said last-named axis and the nip beinglocated in a second plane which is generally perpendicular to thefirstmentioned plane, a subframe pivoted on said main frame to rock on ahorizontal aYis, coating-mirture supply means including an axiallyhorizontal roll carried by said subframe above said main frame axisadapted to contact the applicator roll to supply coating-rnixtnrethereto, the axes of the supply and applicator rolls being located in athird plane intersectiug the first-named plane at an angle which iscloser to 90 than to 0, the axis of said subframe being located belowsaid supply roll axis, the center of gravity of the main frame and partscarried thereby being located in a Vertical plane not materially spacedfrom the axis of said main frame, means for rocltq said main frame toapply pressure to the papercoating nip, and means carried by the mainframe for rocldng said subframe to bring said supply roll into contactWith the applicator roll.

4. in a. paper coating machine, a frame pivoted on a horizontal axis, aroller-coating mechanism including a roll carried by said frame on anaXis parallel to the frame axis and substantially spaced from said.frame axis and so located relative to the frame axis that the center ofgravity of said frame and parts carried thereby including said roll islocated at a point not materially spaced from a Vertical plane extendingthrough the frame aXis, and means for rocking said frame on its axis tomove said roll into and out of operative position, which means iucludesa pair of iluid-pressure-actuated devices connected together to operatein series, one of said devices being of long stroke and the other ofsaid members being of relatively short stroke, the actuation of thelong-stroke device serving to rock the frame and move the roll When thelatter is out of operative position and the short-stroke device beingadapted to adjust the pressure on the roll when the roll is in operativeposition.

5. ln a paper coating machine, a frame pivoted on a horizontal axis, aroller-coating mechanism including a roll carried by said frame on anaxis parallel to the frame axis and substantially spaced from said frameaxis and so 9 located relative to the frame axis that the center ofgravity of said frame and parts carried thereby including said roll islocated at a point not materially spaced from a Vertical plane extendingthrough the frame axis, and means for rocking said frame on its axis tomove said roll into and out of operative position, which means includesa pair of fiuid-pressure-actuated devices connected together to operatein series, one of said devices being of the long stroke piston type, andthe other of said members being of the relatively short stroke diaphragmtype, the actuation of the long-stroke device serving to rock the frameand move the roll when the latter is out of operative position and theshort stroke device being adapted to adjust the pressure on the rollWhen the roll is in operative position, and means for supplying to saidlong-stroke device fluid in such amount and under such pressure as toprevent any improper movement of its piston during control of theroll-pressure by the short-stroke device.

References Cited in the file of this patent UNITED STATES PATENTS2,278,563 Recht Apr. 7, 1942 2,406,056 Barrett Aug. 20, 1946 2,406,057Barrett et al. Aug. 20, 1946 2,513,394 Barrett et al. July 4, 19502,556,032 Faeber June 5, 1951 2,606,520 Hoel Aug. 12, 1952 2,645,199Zonner July 14, 1953

4. IN A PAPER COATING MACHINE, A FRAME PIVOTED ON A HORIZONTAL AXIS, AROLLER-COATING MECHANISM INCLUDING A ROLL CARRIED BY SAID FRAME ON ANAXIS PARALLEL TO THE FRAME AXIS AND SUBSTANTIALLY SPACED FROM SAID FRAMEAXIS AND SO LOCATED RELATIVE TO THE FRAME AXIS THAT THE CENTER OFGRAVITY OF SAID FRAME AND PARTS CARRIED THEREBY INCLUDING SAID ROLL ISLOCATED AT A POINT NOT MATERIALLY SPACED FROM A VERTICAL PLANE EXTENDINGTHROUGH THE FRAME AXIS, AND MEANS FOR ROCKING SAID FRAME ON ITS AXIS TOMOVE SAID ROLL INTO AND OUT OF OPERATIVE POSITION, WHICH MEANS INCLUDESA PAIR OF FLUID-PRESSURE-ACTUATED DEVICES CONNECTED TOGETHER TO OPERATEIN SERIES, ONE OF SAID DEVICES BEING OF LONG STROKE AND THE OTHER OFSAID MEMBERS BEING OF RELATIVELY SHORT STROKE, THE ACTUATION OF THELONG-STROKE DEVICE SERVING TO ROCK THE FRAME AND MOVE THE ROLL WHEN THELATTER IS OUT OF OPERATIVE POSITION AND THE SHORT-STROKE DEVICE BEINGADAPTED TO ADJUST THE PRESSURE ON THE ROLL WHEN THE ROLL IS IN OPERATIVEPOSITION.